#tree {
  display: flex;
}
#tree #tree1 {
  background-color: #ccfffc;
}
#tree #tree2 {
  background-color: #fde5c6;
}
#tree .tree {
  min-width: 50%;
  max-width: 500%;
}
.tree {
  z-index: 66;
}
.tree .line {
  display: flex;
  justify-content: space-around;
  margin-top: 40px;
}
.tree .line .node {
  width: 50px;
  height: 50px;
  line-height: 50px;
  text-align: center;
  border: 2px solid black;
  border-radius: 50%;
  background-color: white;
}
.tree .line .node .drawLine {
  position: absolute;
  border: 1px solid black;
  z-index: -1;
}
.tree .line .null {
  opacity: 0.1;
  border: 2px dashed black;
}
* {
  margin: 0;
  padding: 0;
}
